Sprayers have been developed in the past for mixing two or more liquids to form an anti-adhesive material or a living tissue adhesive and ejecting the mixture to a diseased region of a body.
Known sprayers like this are structured to feed ingredients, solidifiable upon mixed, e.g. a solution containing thrombin and a solution containing fibrinogen, to a diseased region or nearby in a separated state and to apply those while being mixed at the diseased region.
Existing sprayers include a nozzle having inner tubes connected to the spouts of two syringes respectively containing different types of liquids, and an outer tube receiving the inner tubes and allowing sterilized gas to pass through a space with the inner tubes. An example of this sprayer is disclosed in JP-A-2001-57979. Sterilized gas is supplied from a bombe connected to the outer tube through a tube and filled with sterilized gas.
The inner tubes, in the nozzle of the sprayer described in JP-A-2001-57979, each have a liquid orifice opening at a tip through which liquid is to be ejected. The outer tube has two gas orifices opening at a tip for ejecting sterilized gas and arranged therein with the liquid orifices. In this manner, the nozzle of the sprayer described in JP-A-2001-57979 is of a double-tube structure in which the liquid orifices and the corresponding gas orifices are arranged concentrically. Clearances (gaps) are each formed between the liquid orifice and the corresponding gas orifice.
When liquids are ejected together with sterilized gas in the nozzle constructed as noted above, it is possible that the liquid orifices will become eccentric (i.e., will deflect) relative to the gas orifice under a certain condition of pressure and flow rate of sterilized gas and flow rate of each liquid, for example. In this state, the clearance is configured with greater and smaller portions, thus resulting in nonuniform ejection of sterilized gas, i.e., an uneven ejection of sterilized gas.
To prevent this eccentricity of the liquid orifice relative to the gas orifice so as to eject the sterilized gas with relative uniformity, one possibility to consider is to provide a plurality of ribs (convexes) in the inner peripheral surface of the gas orifice which abut against the outer peripheral surface of the liquid orifice and sustain the liquid orifice, with the ribs being arranged intermittently in the clearance.
However, there is a need to form a clearance microscopic in dimension (e.g. smaller than 150 μm) in order to enable relatively uniform ejection of sterilized gas. Thus, it is quite difficult, if not impossible, to provide ribs with accuracy in a manner not to obstruct the relatively uniform ejection of sterilized gas. For example, size variation might result in a plurality of ribs or clearance be filled up by ribs in the course of forming the ribs.